Drawing apparatus



Aug. 14, 1923.

A. W. DARGUE ET AL DRAWING APPARATUS Filed Jan. 29, 1923 2 Sheets-Sheet 1 y w wwg Aug. 14, 1923. 7 11,464,973

A. w. DARGUE ET AL DRAWING APPARATUS Filed Jan. 29, 1923 2 Sheets-Sheet 2 Patented Aug. 14, 1923. l V UNITED-STATES PATENT entice,

, ALGEItNdifWILLIAMIlDAiRGUE nnn rnnpnruon LEWiN DABGUE, or HALIFAX,

ENGLAND;

v DRAWING APPARATUS.

hpplication filed January 29,1923. Serial No. 615,681.

To azl whom it'may concern: V 1 guiding raclis vfor the straight-edge, shown :Beit known that we, A GERNQNJVI IAM in Fig. 1, said Figure 2 also showing an ar- Danonnand FREDERICK LEWIN Danen'nsubrang'ement whereby the straighteedge can be jects of KingGeorgefVxiof Great Britain, removed when desired. -5 residingatlI-Ialifax, inzthe county of York, Fig. 3 is a. section on an enlarged scale, 6

England, vhavelinvented a.:new and useful on the lineA, A, Fig. 1. Improvement :in or .Relating i to Drawing 1 Figs. 4 and 5 are, respectively, aneleva- Apparatus (for which :I' have .filed aption and a plan view of a suitable means for V pli'cation .inmGreat Britain,.:on November 'e'fi'ecting,automaticspacing of the drawing H0 '18, 1921, Patent-No. 188214) o'fiwhich the armsor scalesacross the board {and followingisaspecification; Fig. 6 is another elevation of thespacing 'Our invention in orirelating to drawing @means, showing the parts indifferent posi- V apparatus has reference to what areolniown' tionsfronrsthose shown in Fig. 4- and bein as universall' drawingor drafting machines furnished to facilitatethe description oi 'the 15 and has-for its object to improve upon the action of suchispacingmeans.

40 it is movable.

prsentconstructions. Referring to, the drawings 1 represents a According to, and for the purposes of, our drawing board, and 2,2 toothed racks apinvention we employ a' drawing bo'ard, a plied "to its side edges. These racks are straight-edge'for usetherewith, and-means preferably attached to metal plates 3, see

-20' to maintain the straight edge in true hori- Fig. 2, which are screwed to the edges of zorital *position' a's'it is movedo'ver'th'e sur- :zthe board. The edges of the plates are 'face-o'ftheboard. y p preferably arranged to shroudror "project "Ihe board-may be-supported'on a suitable slightly above the tooth .level of the racks 'stand p rovidedwith mechanism whereby the "and thus prevent the teeth of the :pinions 26 vertical height'o f thei bo'ar'chand its" angular -hereinafter referred to froincoming into jjpositi'o'n, can be adjusted. f contact with *th'e woodwork of the llDOSId.

Z Thestrai ght edge carries aba'r, the upper- A straight-edge 4,.for'use with the board, "edge (if-which is parallel ito the worlring has a handirail15, through which passes a edge ofthestraight-edgefanil"movablealong spindle 6 "havingzonits ends-:pinions 7, 7,

this bar is a plate, on which is pivotzilly adapted to smeshwiththe'racks2,2. The mounted a meinberhaving two arms extendteeth "of the racks and pinions are prefering at right angles and adapted to carry ablyskewed orcut at an angle as shown. straight edge'sorscales. V 3 "Th'eiupper side of the board, at each end Means are provided to enable the 'two- "thereof is provided 'with a guide "pulley 8, 35" armed meniber' orlever to 'be locke'd'in any :andi'ifthe board'ismounted'upon a stand-to 'angularpositiondesired;and means are also p'erniit'its angular position .to :beacljusted,

' provided whereby the plate carrying *the cordsS), 9,attac'hed toathe straight-edge and said In'einber'o-r lever canbe a'utomatically passing'over the pulleys8,' 8, are suitably and regularly-spacedatlo'xigth'eibaronwhioh Weighted to counter-balance the weight of r the straight-"edge and of'the' parts,hereafter.-05 If the board "is mounted on a stand 'as gtobe described, carried thereby. above-setforth; means in the form of cords The ends of the straight-edge areproand weights are provided to counterbalance :vided with pivoted members or brackets 10,

the weighto'fthe straight-edge and o'fthe .10,'carrying'rollers 11,11 which areadapted 5 parts 'ca'rried thereby, when the board o ccutoengage in grooves'lQ, 12 in the undersides pies arve'rtical orangular position. of the racks and hold the straight-edge in 'lhe invention will be more fullyde contact wi'thithe surface of thewboar'd. The

7 scribed with *the aid ofthe accompanying members 10,10 are slotted as at'lO to perdrawing'in which 1 l. mit the rollers 1'1 todrop out of the'grooves M550 Fig. 1 is a plan or front-view are draftwhen the clamping bolts 13 are-.slackened. .10

'ing machine constructed according to the in- The members 10 canthen be moved about vention',the-automatic spaeing meansbeingtheir pivots to carry'the rollers outwards "omitted; I clear of the racks andthestraight-edge can "Fig. "2 "is 5 detail section showing the then be removedfrom theboard. mefhodzofattaching to'theboard the toothed Secured at its-ends to the surfac'e' ofthe N straight edge and spaced at a suitable distance therefrom is a bar 14:, preferably of metal, the upper and lower edges of which are truly parallel to the working edge 1' of the straight-edge. The edge a is the upper edge when the drawing board is mounted in a vertical or inclined position;

Slidable between this bar or runway 14 and the surface of the straight-edge is a plate 15 provided with rollers 16, 16 which are adapted to run on the upper edge of the bar.

' The plate 15 extends a suitable distance below the lower edge of the bar 1st and carries a spring member 17 the ends oi which bear, by suitable rollers 17, 17, against the lower edge of the bar and hold the rollers 16, 16, in contact with the upper edge of the bar.

A suitably shaped bracket 18, secured to the plate 15 by a bolt 19, carries a roller 20 of'suitable material such as rubber which bears upon the front surface of the bar 1 1 and is adapted to take the weight of the plate off the surface of the straight-edge. The plate 15 can, by the above'means, be moved easily and truly along the bar 1 1 from end to end thereof, and the roller 20 bears on the bar with suilicient force to guard against accidental displacement of the plate along the bar.

A centrally disposed bracket 21 serves to stay the centre of the bar or runway 14 and is suitably hollowed out, as shown, on its underside 'to permit of the projecting part of the plate 15 with its spring member 17 and rollers 17, 17, to pass beneath same.

The plate 15 projects a suitable distance above the bar 14 and has its upper edge made semi-circular in shape as shown.

Pivoted on the centre from which the semi-circular edge of plate 15 is struck, is a member having two arms 22, 22, extending at a right angle to each other. These arms are adapted to receive straight-edges on scales 23, 23 and they are of such a length as to extend to about midway of the length of the scales employed, so that by providing attachments, such as screws, 24:, 2 1 at the extreme ends of the arms, and other attachments 25, 25 near the inner ends of the sela-les the latter areheld rigidly without any p The arm 22 carries a spring plunger 26 adapted to engage, when the arm is ap propriately positioned, in one of a series of holes 27 on the plate 15, so as to hold the arms in a definite angular position with respect to the straight-edge. say with the arm 22 vertical or at thirty. forty five or sixty degrees or horizontal. V

The arm 22 carries a Vernier 28 adapted to work in conjunction with a suitably di vided arc 29 on the plate A clamping bolt 30 is provided to enable this arm 22 to be set in any position of fine angular adjustment that may be required, the spring plunger 26 of the other arm being of course held clear of the holes 27 to permit this adjustment to be made. A finger lever 26 is provided to enable the plunger 26 to be so raised. A central knob 31 secured to the two armed lever or member enables the latter to be turned to adjust the set square formed by the straight-edges or scales 23, 23 and to facilitate movement of the apparatus over the surface of the board. i To enable the plate 15 and the parts carried thereby to be automatically spaced along the runway 14:, the bracket'ldmay carry a pivoted member 32 having pivotally at- .80 tached thereto a pawl 33. A-spring 34: connected to the member 32 and .tothe pawl acts to draw the latter inwardly. The end 011116 pawl is formed as a tooth to engage serrations on the surface of the bar 14 which serrations may conveniently be divisions of a measure of length-as indicated in Figs. 1 and 5. V

An extension 32 of the member 32, beyond its pivot centre, carries an adjusting screw 35 adapted to contact with the surface of the plate 15.

Fig. 4 shews the normal position of the spacing apparatus. If the end of the memher 32 be depressed, by finger pressure on the 5 7 button 36, the end of the pawl engages in one of the serrations of bar 14; and forces the plate 15 and parts carried thereby to the right, as illustrated by Fig. 6. On release of 7 member 32, the spring 34 pulls on the pawl and causes member 32 to swing upwardly, until the end of screw 35 abuts onto plate 15, thereby limiting the inward movement of the pawl and positioning it for the next operation. 1

By constructing drawing apparatus as above set forth, we obtain a universal drafting machine without any projections beyond the edges of the board other than the usual overlapping of the set square when the latter is employed in either extreme horizontal po sition. A full length horizontal line can be drawn atany time and parallel angular lines starting from points in the same horizontal plane can be drawn. The scales, if employed, are available acrossthe whole width of the board in any position, either horizontal or angular, and they can be readily locked in any desired position. Y

The details of construction of the parts constituting the. improved apparatus. may vary. l Having thus described our invention, what we claim as new and desire to secure by Letters Patent is The. combination, with a straight-edged member provided with serrations, and a plate slidably mounted on the said member, of a spacing device comprising a depressible spacing arm supported pivotally by the said plate, a pawl pivoted to the spacing arm and engaging with thesaid serrations, an extension arm secured to the spacing arm and projecting on the other side of its pivot from the pawl, a stop screw engaging with the free end portion of the extension arm and bearing on the said plate when the spading arm and its pawl are raised with respect to the said member, and a spring secured between the said spacing arm and pawl and 1 operating to raise them.

In testimony whereof we afiix our signatures.

ALGERNON WVILLIAM DARGUE. FREDERICK LEWIN DARGUE. 

